Influence of photoperiod and temperature on growth, gas exchange, and cold hardiness of yellow cypress stecklings

1994 ◽  
Vol 24 (8) ◽  
pp. 1608-1616 ◽  
Author(s):  
P. Puttonen ◽  
J.T. Arnott

Yellow cypress (Chamaecyparisnootkatensis (D. Don) Spach) stecklings (rooted cuttings) were acclimated for approximately 8 weeks under one of the following photoperiod–temperature treatments: 18 h/10 °C, 18 h/20 °C, 9 h/10 °C, 9 h/20 °C followed by deacclimation in a common environment of 12 h/20 °C for approximately 6 weeks. During acclimation and deacclimation, steckling morphological development, net photosynthesis, transpiration and leaf conductance, and midday shoot water potential were measured. Hardiness was determined by freeze-induced electrolyte leakage. Shoot growth was reduced more by short photoperiods (9 h) than by cool temperature (10 °C) as were net photosynthesis, stomatal conductance, transpiration, and photosynthetic efficiency. Photoperiod-induced cold hardening of shoots and height growth cessation were reversible in warm temperatures (20 °C) and 12-h days, indicating that hardiness induction treatments had no lasting effects on the growth or cold hardiness of this tree species.

1993 ◽  
Vol 23 (12) ◽  
pp. 2537-2547 ◽  
Author(s):  
J.T. Arnott ◽  
S.C. Grossnickle ◽  
P. Puttonen ◽  
A.K. Mitchell ◽  
R.S. Folk

The influence of short-day (9 h) and long-day photoperiods (18 h), and three levels of plant moisture stress (none and dried to predawn shoot water potentials of −1.0 or −1.8 MPa), applied for 7 weeks beginning in mid-July 1990, were studied on greenhouse-grown stecklings (rooted cuttings) of yellow cypress (Chamaecyparisnootkatensis (D. Don) Spach). A series of morphological and physiological measurements were made on the stecklings during and after the treatment period. Moisture stress significantly reduced steckling shoot growth and shoot dry weight by lowering net photosynthesis rates, while short-day photoperiods did not. The most pronounced growth reductions occurred when the treatments were combined, but effects were short-lived, with shoot growth resuming soon after the treatments ended. The short-day and moisture-stress treatment had no significant effect on root dry weight, shoot/root ratio, or water balance ratio. The risk of using moisture stress to control shoot growth in the nursery was low; mortality did not occur until the stecklings had been without water for at least 9 days. Moisture-stress treatments increased steckling root growth potential but had little effect on osmotic adjustment, cell elasticity, dry weight or symplastic fractions, cuticular transpiration, resistance to plant water movement, and relative water content of the shoots; short-day treatments had no influence on any of these parameters. Short days and moisture stress, singly or combined, had little effect on steckling cold hardiness. Steckling gas exchange rates were reduced significantly by low root temperature. In a 6-week controlled-environment simulation of planting-site moisture conditions, no significant differences in steckling net photosynthesis, transpiration, or stomatal conductance were found among nursery treatments; those that had been subjected to moisture stress in the nursery had small growth increases after planting in both wet and dry soil moisture regimes. We conclude that shoot growth of yellow cypress stecklings was controlled in the nursery using 9-h photoperiods and −1.8 MPa predawn shoot water potentials. Improved cold hardiness of the stecklings was not achieved using these nursery cultural methods, but moisture stress did confer some measure of drought resistance immediately after treatment, with higher root growth potential and lower shoot mass.


1999 ◽  
Vol 29 (1) ◽  
pp. 40-46 ◽  
Author(s):  
Johan Westin ◽  
Lars-Göran Sundblad ◽  
Martin Strand ◽  
Jan-Erik Hällgren

Seasonal development of apical mitotic activity and growth in three clones of Norway spruce (Picea abies (L.) Karst.) of the same age and origin but with differences in accumulated height growth and cold hardiness were investigated. The clones showed no consistent difference in mitotic index (MI), either in period or in general levels. The response of MI to temperature differed in spring and fall. Differences in cold hardiness between the clones was not directly coupled to differences in MI. Diameter growth ended earlier in one clone than in the other two clones, and this clone also produced lower numbers of stem units in both lateral and leader shoots. Cessation of diameter growth showed no relation to the duration and level of apical MI. The tallest clone had, as a combined effect of both size and number of stem units, significantly longer leader shoots than the other two clones. The greater leader shoot growth of the tallest clone relative to the other two clones during 1987-1996 was also most prominent after years with sudden drops in fall minimum temperatures to below ca. -12°C (median; interval: -11 to -13°C), following several weeks with mean temperatures above 3°C.


1994 ◽  
Vol 24 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Conor O'Reilly ◽  
J.N. Owens ◽  
J.T. Arnott ◽  
B.G. Dunsworth

Western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings grown in two different container cavities that received four different dormancy induction treatments, short (SD) or long days (LD) in combination with moisture stress (D) or no stress (W) in the greenhouse, and lifted and placed in cold storage (November, January, or March), were planted on two adjacent coastal reforestation sites in British Columbia and monitored for survival and morphological development. Survival was greatest in seedlings grown in the larger cavities in the greenhouse, in seedlings lifted in March, and in seedlings not treated to moisture stress. Seedling shoots had more stem units on the southeast than the northwest site, but the amount varied with nursery treatment. Seedlings from the LD treatments produced more stem units during free growth and lammas growth than those from the SD treatment. Nevertheless, most shoot growth was predetermined in the buds during nursery culture, accounting for a minimum of 67% of the final number of stem units. Stem unit length (SUL) was longer in seedlings on the southeast site than on the northwest site for those treated to LD in the nursery. Seedlings treated to short days showed the reverse pattern (SDW) to this, or were unaffected by site (SDD). Shoots and needles were shortest for seedlings from the SDD treatment and for those lifted in November. Shoot growth was greatest for seedlings lifted in March and for those treated with LD, mainly owing to their longer SUL. Lammas growth was most frequent in seedlings from the smaller cavities, and in those from the November and March lifts.


1986 ◽  
Vol 3 (3) ◽  
pp. 91-93 ◽  
Author(s):  
Robert E. Farmer ◽  
Heather A. Foster ◽  
Olenka Bakowsky ◽  
Brian MacDonald ◽  
Gwenoth O'Reilly ◽  
...  

Abstract Greenwood cuttings from greenhouse-produced tamarack seedlings and 3- to 10-year-old tamarack wildlings transplanted from natural stands in north-western Ontario were rooted under mist in peat-vermiculite. Eighty-five percent of cuttings from seedlings rooted; treatment with indolebutyric acid increased number of roots per cutting, but not rooting percent. At 6 weeks after planting, rooting of cuttings from wildlings averaged 66%, and at 12 weeks, 91%. Twelve-week rooting percent of cuttings from individual ortets ranged from 12 to 100, but cuttings from the majority of ortets exhibited 100% rooting. Nearly all rooted cuttings survived overwintering outdoors and initiated normal shoot growth after forcing in mid-winter. The described propagation system is recommended for production of container stock for tamarack plantations. North. J. Appl. For. 3:91-93, Sept. 1986.


2009 ◽  
Vol 39 (10) ◽  
pp. 1821-1834 ◽  
Author(s):  
B. J. Hawkins ◽  
M. Stoehr

Thirty-two full-sib families of coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) with a range of predicted breeding values were monitored for growth rate, phenology, and cold hardiness over 2 years on two sites to investigate if other traits are being selected when family selection is based on height. Significant differences among families existed in most phenological, growth, and cold-hardiness traits. On average, taller families burst bud later but did not have significantly different growth rates or length of growing period than other families. We found no significant correlations between family date of bud burst and cold hardiness in late spring or between duration of shoot growth or height and autumn freezing damage. Family differences in freezing tolerance were greatest in September and October. In these months, family current-year leaf nitrogen was positively correlated with cold hardiness. Families that were most hardy in the autumn were not the most hardy families in spring. We conclude that, for the studied breeding series, selection based on height does not have a significant impact on cold hardiness. We found no consistent relationships between phenological, growth, or cold-hardiness parameters and final height that could explain family ranking by height. Relationships between grandparent elevation and dates of bud burst and cold hardiness were observed.


1984 ◽  
Vol 14 (5) ◽  
pp. 644-651 ◽  
Author(s):  
A. N. Burdett ◽  
L. J. Herring ◽  
C. F. Thompson

Observations were made on the growth of white spruce (Piceaglauca (Moench) Voss) and Engelmann spruce (P. engelmanni Parry), each planted at a single location in the interior of British Columbia. In both species bareroot stock (either 2 + 0 seedlings or 2 + 1 transplants) with a low root growth capacity made only limited height growth during the first two seasons after planting. In the first season, many short stem units were formed, whereas in the second season, stem units were much longer but many fewer. The length of needles formed after planting by the bareroot trees was, in the first season, only about half that of needles formed the previous year in the nursery. Needle length increased slightly in the 2nd year. Container-grown trees (1 + 0 seedlings from 336-mL containers), which had a high root growth capacity, made relatively good height growth in the first season when they formed long needles and stem units. Height growth by these seedlings was much less in the second season, however, as were needle length and stem unit number, but not stem unit length. Application of slow release N,P, and K fertilizer at planting improved shoot growth by bareroot trees more in the second season than the first. In contrast, the container-grown stock made a large shoot growth response to fertilization in both the first and the second seasons. The results are consistent with the hypothesis that, as root establishment proceeds, shoot growth tends to be limited by the supply, first of water, then of mineral nutrients. This implies that the early growth of planted spruce can be maximized by using stock with a high root growth capacity, or other adaptations to drought, and applying slow release fertilizer at planting. Observations on the white spruce revealed an acceleration in shoot growth by both stock types during the third season. This followed the establishment, by the end of the second season, of root systems several metres in diameter. A large difference in height: diameter ratio, observed at the time of planting, between the container-grown and bareroot white spruce disappeared entirely in the course of the first three growing seasons.


1993 ◽  
Vol 71 (8) ◽  
pp. 1087-1092
Author(s):  
Salim N. Silim ◽  
Robert D. Guy ◽  
Denis P. Lavender

Short-term effects of the plant growth retardant mefluidide on drought resistance were investigated in seedlings of western red cedar (Thuja plicata Donn), yellow cedar (Chamaecyparis nootkatensis D. Don), and white spruce (Picea glauca (Moench) Voss). Mefluidide was applied as a root drench at concentrations of 0, 0.1, and 0.4 mg∙L−1. Following this, seedlings were stressed by withholding water for a period of up to 7 days and then watering regularly thereafter. Stomatal conductance of the mefluidide-treated seedlings decreased significantly and remained lower than the control seedlings throughout the stress period. As a result of the decreased conductance, shoot water potentials in mefluidide-treated seedlings remained higher throughout the stress period. There was a decrease in net photosynthesis that was partially caused by stomatal limitations, the severity of which depended upon the concentration of mefluidide applied. Mefluidide treatment also resulted in an accumulation of abscisic acid in all three species, and this may have been responsible for the effects on stomatal conductance and water relations. In contrast, the mefluidide-treated seedlings had the highest rates of photosynthesis after rewatering, resulting primarily from a promotion of stomatal opening. Key words: stomatal conductance, water potential, photosynthesis, plant growth inhibitors, abscisic acid, cold hardiness.


1975 ◽  
Vol 23 (1) ◽  
pp. 27 ◽  
Author(s):  
KW Cremer

The growth and development of shoots of Eucalyptus regnans F. Muell. trees up to 8 m tall growing in their natural environment in central Tasmania were studied continuously for 3 years and related to climatic factors. The influences of temperature were further investigated by experiments with seedlings in a phytotron. Height growth was practically nil in winter and greatest in summer. Throughout the year weekly rates of height growth were closely related to weekly mean maximum air temperatures, increasing from nil or slight at 10�C to peak rates at the highest temperatures experienced (25°). Substantial diameter increments were observed in all seasons and their relation to temperature was relatively weak. There was no positive relation between weekly growth in height or diameter and weekly precipitation. Bud and shoot growth were characterized by continuity of development of all organs throughout the growing season. The youngest of the leaves and internodes which had emerged before winter from the bud resumed growth in spring, but did not reach the lengths achieved by those leaves and internodes which emerged from the bud after winter. It was only by this morphological feature that the boundaries of the annual shoot were identifiable. In agreement with the field observations, the growth of seedlings in glasshouses was found to be slow at day/night air temperatures of 10/5°C and to increase steeply with temperatures to 24/19°. Amongst the notable morphogenic influences associated with increasing temperatures in the glasshouses were poorer root development relative to top growth, thinner and smaller but more numerous leaves, and shorter and more numerous internodes. The elongation of individual leaves and internodes was faster but considerably less prolonged as temperatures increased. The E. regnans seedlings tested failed to prove thermoperiodically sensitive. It is concluded that the dormancy in shoot development observed in the field during winter is due to quiescence imposed by low temperatures, and that in the Tasmanian environment the pattern of growth and development of the vegetative shoots of E. regnans is directly and predominantly controlled by air temperatures throughout the year.


1999 ◽  
Vol 29 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Raynald Paquin ◽  
Hank A Margolis ◽  
René Doucet ◽  
Marie R Coyea

Growth and physiology of layers versus naturally established seedlings of boreal black spruce (Picea mariana (Mill.) BSP) were compared 15 years after a cutover in Quebec. During the first 8 years, height growth of seedlings was greater than that of layers, averaging 10.4 and 7.0 cm/year, respectively. For the last 5 years, annual height growth of layers and seedlings did not differ (25 cm/year; p > 0.05). Over the entire 15-year period, total height growth of seedlings (251 cm) was greater than that of layers (220 cm), although total height did not differ (p > 0.05) over the last 6 years. During the 15th growing season, there were no differences (p > 0.05) for predawn shoot water potential, stomatal conductance, net photosynthesis, intercellular to ambient CO2 ratio, water use efficiency, and hydraulic conductance between layers and seedlings. For diurnal shoot water potential, seedlings showed slightly less stress than layers on two of the four sampling dates. Thus, in the first few years following the cutover, the slower growth observed for layers indicated that they had a longer acclimation period following the cutover. Afterwards, similar height growth, total height, and physiological characteristics of the two regeneration types indicated that layers can perform as well as naturally established seedlings.


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